Build the classic Sierpinski fractal by recursion, chaos game, or triangle removal. Change depth and style, watch it grow step by step, or export your pattern as an image.
Recursion: split each triangle into three by joining midpoints and skip the center. Chaos game: pick a random vertex, jump halfway toward it, repeat. Triangle removal: start filled, then repeatedly remove the central quarter. All three produce the same limit shape.
Each step keeps three of four smaller triangles. Remaining area is (3/4)n after n steps, so it tends to zero while the perimeter grows. The fractal dimension is log 3 / log 2.
Color odd entries in Pascal's triangle black and even white: the Sierpinski pattern appears. The same pattern shows up in Rule 90 one-dimensional cellular automata.
